INS
TALLER
US
ER
MAINTEN
AN
CE TECHNI
CI
AN
16
1.13 TABLES OF RESISTANCE FACTORS AND EQUIVALENT LENGTHS “GREEN SERIES”.
TYPE OF DUCT
Resistance
Resistance
(R)
Length
in m of concentric pipe
Ø 80/125
Concentric pipe 80/125 Ø m 1
2.1
1
Ø 80/125 90° concentric bend
3.0
1.4
Ø 80/125 45° concentric bend
2.1
1
Terminal complete with concentric horizontal intake-exhaust
Ø 80/125
2.8
1.3
Terminal complete with concentric vertical intake-exhaust
Ø 80/125
3.6
1.7
90° concentric bend Ø 80/125 with inspection
3.4
1.6
Stub pipe with inspection Ø 80/125
3.4
1.6