Information for installation
Chimney
25
7
Information for installation
7.1
Chimney
7.1.1
Planning and layout
Required chimney diameter
Please note that in partial-load operation the exhaust temperature is lower and the large chimney diameters,
normally used for solid fuel, are no longer ideal. If the cross section is too large, the flue gas no longer safely rises
from the chimney opening and may flow along the roof and sink to the windows of the living quarters.
The flue pipe from boiler to chimney must be executed as per the requirements in the table. A flue pipe with
3 m length and two 90° bends was assumed for the calculation. For some boilers a smaller chimney dimension
(corresponding to the minimum diameter) can also be used. These values are listed in brackets.
Example: HACK VR 250 with 10 m chimney height and DN250 flue pipe => a chimney with 30 cm diameter is
required. Alternatively, a chimney with 28 cm diameter can be used.
No cross-sectional taper is permitted, such as a DN300 flue pipe in a chimney with a 28 cm diameter.
Diameter of the flue pipe from
boiler to chimney
Chimney height above
the boiler room floor
Required chimney diameter in cm
HACK VR 250
DN 250
7 m
35
a
DN 250
8 m
35
a
DN 250
9 m
35 (30)
DN 250
10 m
30 (28)
DN 250
11 m
30 (28)
DN 250
12 m
30 (28)
DN 250
13 m
30 (28)
DN 250
14 m
30 (28)
a. For boiler outputs over 30 kW and chimney heights under 8 m, a chimney joint tilted 45° can help achieve the required draught of 5
Pa at full load with acceptable cross-sections (one size smaller than indicated in the table).
Diameter of the flue pipe from
boiler to chimney
Chimney height above
the boiler room floor
Required chimney diameter in cm
HACK VR 333
HACK VR 350
DN 300
7 m
40
a
DN 300
8 m
40
a
DN 300
9 m
40
DN 300
10 m
35
DN 300
11 m
35
DN 300
12 m
35
DN 300
13 m
30
DN 300
14 m
30
a. For boiler outputs over 30 kW and chimney heights under 8 m, a chimney joint tilted 45° can help achieve the required draught of 5
Pa at full load with acceptable cross-sections (one size smaller than indicated in the table).