30
Separate outlet on flat wall
1. Separate outlet creates a zone from the
axis of the outlet with a width a = 0.5 m,
radius b = 1.0 m and height c = 5.0 m.
Fig. 21 Diagram of formation of zone
with separate outlet of fl ue duct
2. If the axes of the outlet are at a distance
of d > 0.3 m beneath the upper part of
the window construction, the created
zone must not overlap with the surface
formed by the window. At a distance of <
0.3 m the zone bordered by the radius b
may overlap with the upper part of the
window.
Fig. 22 – Diagram of formation of zone
from axis of outlet of fl ue duct located
in vicinity of upper part of window
Fig. 21
Examples of placing fl ue ducts according to appendix no. 7 of
SR Government Regulation no. 92/1996 Coll.
Safety measures
The distance between any fl ammable
material and the fl
ue gas part of a
separate tubing must be such that the
surface temperature of this material does
not exceed 80°C.
Combustion gases outlets must not be
located in the following places:
• with the danger of explosion (as defi ned
by STN 33 2320)
• in the building’s interior (attics, corridors,
staircases, etc.)
• which can be closed, e.g. in gateway
passages, etc.
• underground structures (even when they
constitute no obstacle and are open),
such as tunnels, subways, etc.
These principles of prohibiting combustion
gases outlet locations should be
reasonable applied also to the location of
a separate air supply intakes.
A hole in the wall for the dual tubing for
removal of combustion gases and supply
of combustion air must be made with big
enough clearance (120 – 150 mm) and
after installation the hole must be sealed
using a building technology. Sealing must
be done using non-fl ammable materials
(degree of fl ammability A according to STN
73 0823), such as for instance brickwork
plaster, gypsum, etc. A passage through a
fl ammable wall or ceiling must be treated
as described in the fi rst paragraph of this
section.
Important:
It is prohibited to insert inside
the fl ue any objects restricting the com-
bustion gases fl ow (e.g. various types of
exchangers to utilise residual heat). Flue
is not part of the boiler delivery.