Max. height of flue in m
120
140
160
180
200
220
240
260
0
5
10
15
20
25
30
Required total draught in Pa for the burner selection
(boiler and flue pipe)
280
300
40
60
90
50
70
80
60
70
80
10
25
20
20
45
40
30
90
248 kW DN 200
314 kW DN 200
408 kW DN 200
508 kW DN 200
1
System size DN 200
1
Measured from the height of the flue outlet on the boiler to the top
edge of the flue system.
160
180
200
220
240
260
Required total draught in Pa for the burner selection
(boiler and flue pipe)
280
300
508 kW DN 250
320
340
635 kW DN 250
408 kW DN 200
Max. height of flue in m
0
5
10
15
20
25
30
1
System size DN 250
1
Measured from the height of the flue outlet on the boiler to the top
edge of the flue system.
Assumptions:
■ Length of the connection piece 2 m
■ 3 bends with 87° (including support bends)
■ Diameter of the connection piece DN 200
Example:
Vitocrossal 300 with 314 kW; height of the flue pipe 16 m. The following
diagram illustrates how to read the required total draught (boiler and
flue system) from the above diagram.
Design information
(cont.)
Gas condensing boilers
VIESMANN
33
5822 449 GB
8
