34
8.8.5
E
XAMPLE
C:
T
WIN PIPE SYSTEM WITH WALL MOUNTED AIR DUCT
.
Calculation example:
The total resistance is less than 200 Pa, so this is acceptable.
Boiler type:
S-CB
+
550
Flue gas
Diameter: 250 mm.
Number
Pa
Pa total
Straight tube m¹
total
8,5
1,0
8,5
T-piece
outlet
1
12,2
12,2
Bend
90°
2
4,7
9,4
Flue outlet
Zeta=1,5
1
20,3
20,3
Total resistance flue gas outlet:
50,4
A
ir
su
pp
ly
Diameter: 250 mm.
Number
Pa
Pa total
Straight tube m¹
total
5
0,7
3,5
T-piece
inlet
1
2,0
2,0
Bend
90°
2
3,6
7,2
Air inlet
Zeta=1,3
1
13,3
13,3
Total resistance air supply:
26,0
Total resistance flue gas outlet and air supply:
76,4 Pa
INLET AIR MUST BE
CLEAN AND FREE OF
WATER. ALWAYS USE
A WIRE MESH TO
PREVENT DEBRIS
BEING DRAWN INTO
THE AIR INLET.
MAKE SURE THAT
AIR INLET AND
FLUE GAS OUTLET
ARE IN THE SAME
PRESSURE AREA.
WIND CAN HAVE A
LARGE EFFECT
ON WALL
TERMINAL
PRESSURE.
Pressure drop flat T-piece
equals one 45° elbow
