30
8.8
S-CB
+
400 & 550 air inlet / flue gas outlet calculation examples
The load of the boiler is influenced by the resistance of the air supply and the discharge system. The diameter and
length of both air supply and flue gas pipes needs to be designed accurately to decrease the possible power loss of
the boiler.
Calculation examples
In the following, five calculation examples are given for determining the maximum length of the flue gas and air supply
pipes.
A: Twin pipe system with separate pipes for flue gas and air supply.
Air supply roof mounted.
B: Single pipe system for flue gas outlet only.
Air supply from boiler room.
C: Twin pipe system with separate pipes for flue gas and air supply.
Air supply wall mounted.
D1 and D2: Twin pipe system with concentric flue gas outlet - air inlet.
8.8.1
F
LUE GAS AND AIR SUPPLY RESISTANCE TABLE
-
CONCENTRIC PARTS
Just one specific concentric roof terminal has been measured and approved to be used with the S-CB
+
400 and 550.
Below mentioned values concerns only this specific concentric roof terminal. An eccentric adapter has to be used at
the flue gas outlet of the boiler to avoid moisture agglomeration. See example D in chapter 8.7.6
Flue gas
Ø [mm] *
resistance [Pa]
S-CB
+
400
S-CB
+
550
Concentric roof terminal
200 / 300
56,5
106,6
Condensate trap
200
3,7
6,6
Flue gas eccentric adapter
180>200
0,9
1,7
Air inlet
Ø [mm] *
resistance [Pa]
S-CB
+
400
S-CB
+
550
Concentric roof terminal
200 / 300
28,6
54,0
Concentric adapter air supply
180>200
4,3
7,6
Concentric flue gas
outlet and air inlet parts
Concentric
roof terminal
Air supply
concentric
adapter
Flue gas
excentric
adapter
Condensate
capture
