Flue Gas Routed Through A Flue Gas Header Inside A Shaft With Flue Cascade Set - Buderus Logamax plus GB162 Technical Manual

9 Flue systems for open flue operation
9.7

Flue gas routed through a flue gas header inside a shaft with flue cascade set

Appliance type B (formerly B
23P
Observe the general information on page 108 ff.
For cascades with Logamax plus GB162 gas condensing
boilers, a special installation room is required for a rated
output in excess of 100 kW, (according to the
Muster-Feuerungsverordnung [Germany] (
Mode of operation
• Positive pressure operation when all gas condensing
boilers operate at full load.
• Negative pressure operation as soon as one gas
condensing boiler is shut down.
The negative pressure operation at partial load ensures
that the flue gas cannot re-enter the room via the gas
condensing boilers. This makes shut-off dampers
unnecessary.
Adequate combustion air supply
According to the Technical Rules for Gas Installations [in
Germany] DVGW-TRGI 2008, a vent of at least 150 cm
2
plus 2 cm for every kilowatt in excess of a total rated
output of 50 kW towards the outside must be provided in
the installation room accommodating a cascade of
Logamax plus GB162 gas condensing boilers. This
cross-section can be split over two vents (
page 110).
Maintain the minimum dimensions of the shaft
cross-section to ensure that the remaining cross-section
is adequate for the installation and the secondary
ventilation of the flue (
Minimum shaft cross-section
Flue
Cross-section,
Ø
[mm]
110
125
160
200
250
315
Table 56 Minimum shaft cross-section for the installation
of the flue (
Sizing applies including the flue gas header downstream
of the last appliance with a length of up to 2.5 m, the
support bend in the standard shaft set and one additional
90° diversion.
In the case of several additional diversions, carry out a
calculation according to DIN-EN13384-2.
126
)
23
page 110).
tab. 44,
tab. 56).
Minimum shaft dimensions
Cross-section,
circular rectangular
[mm] [mm × mm]
160 140 × 140
180 180 × 180
200 200 × 200
250 250 × 250
330 310 × 310
400 380 × 380
fig. 101, page 116)
If the combination of GB162 appliances varies from those
in the sizing table (
of different Logamax plus appliance types, carry out a
calculation to DIN-EN 13384-2 when using a flue
cascade.
Inspection apertures and condensate drain
Allow for inspection apertures in accordance with
applicable regulations. A drain for condensate from the
flue is always required. The required condensate drain
with siphon is part of the Buderus flue cascade sets.
Flue cascade set
2
1)
1)
Fig. 115 Installation version (dim. in mm)
A Flue gas
B Secondary ventilation
C Ventilation air
P Inspection aperture
1)
Vent to the outside: (
Special installation room > 100
Maximum permissible length
Typical appliance combinations are collated in table 57.
6 720 645 821 (2010/09) – Logamax plus GB162
tab. 57) or there are combinations
21+22
≥ 400
23
26
24
20
(27)
2–10 12–16 12–16 11
1 1 1 1
C
B
tab. 44, page 110)
page 111
A
≥ 1000
L
17–19
P
6 720 642 463-78.1il