4
Set-up and installation
Installation and operating instructions
19
Gas Combi Unit
Floor-standing gas condensing boiler with integrated heat storage
008.1543899_02 – 04/2019 – EN
▪ The flue gas discharge to the outside runs through the chimney or
an installation shaft. If the connection line between the GCU com-
pact and the installation shaft is single-walled or not completely
surrounded by combustion air, a
ventilation opening
to the out-
side of at least
150 cm
2
is required.
Appropriate measures must be taken to ensure that the burner
cannot be operated if the ventilation opening is closed.
▪ The installation shaft where the flue gas line runs must be rear
ventilated. There must be a rear ventilation opening of at least
150 cm
2
in the lower area.
The cross-section of this installation shaft must be dimensioned so
that the following minimum distance is maintained
between the
external wall of the flue gas line
and the
internal face of the in-
stallation shaft
:
▪ with a rectangular shaft cross-section:
2 cm
▪ with a round shaft cross-section:
3 cm
.
The rear ventilation opening must not be located in rooms where a
negative pressure is generated (e.g. by controlled apartment vent-
ilation, a tumble dryer, etc.).
▪ Device type C
53
, C
83
4.2.3
Ambient air-dependent mode
Installation variant 6
The GCU compact can also be connected with ambient air. Thereby,
only the inner flue gas pipe (plastic pipe Ø 60 mm) of the concentric
air/flue gas pipe is connected to the flue gas line. The device sucks
the combustible air from the installation room through the ring-
shaped gap of the jacket pipe.
The same conditions apply to the flue gas routing into the open air,
shaft dimensioning and rear ventilation as in
. A
ventila-
tion opening
into the open air of at least
150 cm
2
is mandatory.
▪ Device type B
23
, B
23P
, B
33
, B
53
, B
53P
INFORMATION
In some cases, the resonance in the flue gas system can
amplify the noise at the mouth of the flue gas duct. The
noise level can be effectively reduced by using a silencer
(
DN 80: E8 MSD
or
DN 110: E11 MSD
).
4.2.4
Additional information on the device type
in accordance with CEN/TR 1749
INFORMATION
We basically recommend installing the GCU compact re-
gardless of the ambient air (device type C) and with con-
centric air/flue gas guides (see
). Other per-
missible applications of the air intake and flue gas dis-
charge are not described in detail in these instructions.
Special requirements that exist for such systems based on
EN 15502 -2-1 are listed below.
C
13
:
▪ Horizontal openings for flue gas outlet and supply air inlet
▪ Openings within a square of 50 cm × 50 cm
C
33
:
▪ Vertical openings for flue gas outlet and supply air inlet
▪ Openings within a square of 50 cm × 50 cm
▪ Spacing of opening levels < 50 cm
C
43
:
▪ Connection of more than one device to a common air/flue gas sys-
tem that is part of the building
▪ Vertical opening for the flue gas outlet and supply air inlet
▪ Openings within a square of 50 cm × 50 cm
▪ Spacing of opening levels < 50 cm
▪ Suitable calculated dimensioning verification required because va-
cuum prevails in the case of the flue gas inlet into the common air/
flue gas system. The flue gas must be discharged with a natural
draught.
▪ For data on dimensioning, see
.
▪ Condensate flow from the common air/flue gas system must not
be discharged through the device.
C
53
:
▪ Vertical opening for the flue gas outlet
▪ Opening for the supply air inlet into different pressure area pos-
sible.
▪ Openings must not be installed on opposite walls of the building
C
63
:
▪ Connection to a separately approved and marketed flue gas/sup-
ply air system if allowed by national law.
▪ This allows all other described installation forms to the realised for
device type C if the conditions of the respective installation form
are met.
▪ If the dimensions of the system used differ from those described in
), a suitable arithmetical dimension-
ing verification is required.
▪ For data on dimensioning, see
.
▪ Properties and possible applications of the pipe system:
▪ Minimum requirements according to
▪ Condensate flow into the device allowed with single assign-
ment, not allowed with multiple assignment.
▪ Maximum combustion air temperature: 60 °C
▪ Maximum allowed flue gas recirculation current under wind con-
ditions: 10 %
C
83
:
▪ Connection of one or more devices to an underpressure flue gas
system that is part of the building.
▪ Vertical opening for the flue gas outlet
▪ Air supply feed via the associated second
(4)
pipe
▪ Opening for the supply air inlet into a different pressure area pos-
sible.
▪ Suitable arithmetical dimensioning verification required because
vacuum prevails in the case of the flue gas inlet into the common
air/flue gas system.
▪ For data on dimensioning, see
.
▪ Properties and application options of the flue gas system:
▪ Minimum requirements according to
for pressure class)
▪ Condensate flow into the device allowed with single assign-
ment, not allowed with multiple assignment.
C
93
:
▪ as for C
33
, but
▪ Connection of the supply air pipe to an existing vertical shaft (e.g.
chimney) that is part of the building.
▪ The cross-section of this installation shaft must be dimensioned so
that the following
minimum distance
must be maintained
between the external wall of the flue gas line
and the
internal
face of the installation shaft
:
▪ with a rectangular shaft cross-section:
2 cm
▪ with a round shaft cross-section:
3 cm
(4)
If the air supply pipe was used beforehand as a flue gas pipe or chimney of an oil or solid fuel furnace, it should be cleaned
prior to use as an air supply pipe.
Summary of Contents for GCU compact Series
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