Structural Unit; System Certification; Balanced Flue Operation - Viessmann Vitodens series Technician Manual

Flue systems
The following requirements regarding design and installation apply to
flue systems for condensing combustion equipment:
Prior to starting work on the flue system, your heating contractor
should confer with the flue gas inspector responsible [where
1
applicable].
Gas combustion equipment must be connected to the domestic chim-
ney stack on the same floor where it is installed (no transition through
separating ceilings).
Here, differentiation is required as to whether the condensing boiler
should be sited in the living space (occupied rooms) or outside the
living space (installation room).

Structural unit

The aforementioned conditions are generally met when CE-designa-
ted flue systems (accessories) are used together with the Vitodens.
The following Viessmann balanced flue systems for balanced flue
operation are tested to DVGW and are CE-designated as a single
structural unit with the Vitodens:
■ Vertical roof outlet
■ External wall connection
■ Horizontal roof outlet
■ External routing through a coaxial pipe
Advantages of single structural units:
■ No calculated function verification for flue pipes to DIN EN 13384 is
required for individual cases
■ Simplified visual inspection by the local flue gas inspector every two
years
■ No additional approval certificate by the flue pipe manufacturer is
required

System certification

System certification to DVGW-VP 113 and EC Gas Appliances Direc-
tive 2009/142/EC in conjunction with PPs flue pipes offered by Sko-
berne

1.2 Balanced flue operation

The sealed combustion chamber of the Vitodens gas condensing boil-
ers enables their use in balanced flue operation. These boilers are
categorised as C , C , C
13x 33x
2008.
A common approval for the Vitodens and balanced flue system
applies to this type of equipment.
The tightness test (overpressure test) by the flue gas inspector during
commissioning as well as the verification of the "General Building
Regulations approval" by the DIBt may be omitted for this type of con-
struction.
Every approved flue system can be used for type C
is not tested together with the boilers.
Maintain the dimensions specified on pages 11 to 20. The com-
bustion air is supplied and the flue gas extracted through one concen-
tric coaxial pipe (balanced flue system). The combustion air is supplied
through the annular gap between the external aluminium ventilation
air pipe and the flue pipe. Flue gases are extracted through the internal
plastic pipe (PPs).
For balanced flue systems tested together with the wall mounted gas
boiler, there is no requirement for a tightness test during commission-
ing by the flue gas inspector.
VIESMANN
4
, C , C or C according to TRGI
43x 53x 63x 83x
. This flue system
63x
Siting the Vitodens in the living space is feasible, subject to the flue
inside the living space being routed inside a protective pipe and being
surrounded by ventilation air (balanced flue system, balanced flue
operation).
As a special case, an installation inside the living space is also feasible
for open flue operation, provided a connection piece with secondary
ventilation up to the shaft (operation with interconnected room air sup-
ply) is provided (see page 32).
In a non-living space, the flue may also be installed inside the instal-
lation room without secondary ventilation. However, the installation
room would then require an adequately sized vent to the outside (acc.
to TRGI 2008).
Rated output up to 50 kW:
2 2
150 cm or 2 × 75 cm
Rated output above 50 kW (e.g. Vitodens 200-W, from 60 kW, or multi
boiler systems):
150 cm 2 plus 2 cm 2 for each kW above 50 kW
The plain flue must be type approved by the Deutsches Institut für
Bautechnik (DIBt) [Germany] (open flue operation).
The flue available as an accessory is CE-designated and approved to
DIN EN 14471.
Vitodens 200-W CE-0085BR0432
Vitodens 222-F CE-0085BU0051
Vitodens 222-W CE-0085BR0432
Vitodens 242-F CE-0085BU0051
Vitodens 300-W CE-0085BR0433
Vitodens 333-F CE-0085BU0052
Vitodens 343-F CE-0085BU0052
Vitosolar 200-F CE-0085CM0184
We recommend that your heating engineer carries out a simple tight-
ness test during the commissioning of your system. For this it would
be sufficient to check the CO concentration in the combustion air at
2
the annular gap of the balanced flue pipe. The flue is considered suf-
ficiently gas-tight if the CO concentration in the combustion air is no
2
higher than 0.2 %, or if the O concentration is at least 20.6 %.
2
Check the flue system for tightness by pressure testing if higher CO
or lower O values are established.
2
In conjunction with the concentric coaxial pipe (balanced flue system),
the surface temperature of the Vitodens or that of the balanced flue
system will never exceed 85 ºC. Therefore, clearances to combustible
components according to TRGI are not required.
For boiler types C and C , the DIBt-approved flue pipes from
63x 43x
Viessmann or alternative DIBt-approved flue pipes by other manufac-
turers may also be used.
Use a condensate trap above the boiler flue connection if an aluminium
flue pipe is installed. Install the connecting lines with a fall of at least
3° to the boiler.
The balanced flue system is CE-designated and approved to DIN
EN 14471 (see page 6).
The boiler casing creates a system that is sealed against its surround-
ings. Any leaks caused by escaping flue gas are returned via the com-
bustion air, thereby preventing flue gas from entering the living
space.
2
VITODENS