Buderus Logamax plus GB162 Technical Manual page 113

Shafts for flues
Shafts for flues must not be used for any
other purpose.
Flues that bridge several floors must be arranged in their
own shafts inside buildings.
Exceptions
• Flues in building categories 1 and 2, provided that the
flue is not routed through more than one utility unit.
Building categories 1 and 2 are those with a height to
the top edge of the floor on the highest storey that
could house an installation room of no more than 7 m
on average above ground level, and with no more than
two utility units of no more than 400 m
• Flues with a single connection inside the room where
the combustion equipment is installed or
• Flues operated with negative pressure:
– that offer a fire resistance of at least 90 minutes (ID
L90 or higher) and
– in building categories 1 and 2 that offer a fire
resistance of at least 30 minutes (ID L30 and
higher).
Several flues in a common shaft are only permissible if:
• the flues are made from non-combustible materials or
• the associated combustion equipment is installed on
the same floor or
• a transfer of fire between floors is prevented through an
automatic shut-off facility or other measures or
• the flue has received general Building Regulations
approval.
These shafts must offer:
• a fire resistance of at least 90 minutes and
• in building categories 1 and 2, a fire resistance of at
least 30 minutes.
6 720 645 821 (2010/09) – Logamax plus GB162
Routing solar lines through existing shafts for flues
Deviating from para. 7 sect. 5 MFeuVO [Germany],
retrospective routing of solar lines in existing flue shafts
can be acceptable under the following conditions:
• The retrospective routing of solar lines in existing flue
shafts is limited to building categories 1 and 2 (para. 2
sect. 3 sentence 1 no. 1 and 2 MBO) and to solar lines
that transport water only.
• The heat transfer of solar lines and fittings should be
limited by means of thermal insulation in accordance
with the Energy Savings Order dated 16 November
2001, appendix 5, table 1 [Germany]. Alternatively,
from a building regulations point of view, the minimum
thickness of thermal insulation can also be halved. The
insulating layers must be resistant to the maximum
2
in total or
applicable temperatures inside the solar lines as well
as to the temperature stresses resulting from the flue
system.
• Safeguard the reliable operation of the combustion
system through a calculation in accordance with
DIN EN 13384-1: 2003 03.
• The inside wall of the shaft must be smooth and free
from protrusions; all-round adequate secondary
ventilation (annular gap) of the flue must still be
ensured after the installation of the solar lines. Ensure
the stability of the flue system as well as the permanent
security of the solar lines and the sensor lead.
Permanently prevent any contact between the flue and
the thermally insulated solar lines.
• The clearance between the solar line (including thermal
insulation) and flue line must be:
– at least 2 cm for flues with circular cross-sections
– at least 3 cm for flues with circular cross-sections
– at least 3 cm for flues with rectangular
• Using appropriate material, seal the remaining
cross-sections in the shaft wall apertures through
which the solar lines are routed.
• The solar lines including their thermal insulation must
correspond to the requirements of the flue where their
temperature resistance is concerned.
Flue systems for open flue operation
inside a rectangular shaft
inside a circular shaft and
cross-sections inside a rectangular shaft.
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