Rinnai E- Series, Installation & Servicing Instructions Manual, Page: 37 / 92

Installation & Servicing Instructions Rinnai E-Series
37
Calculation of equivalent length vent system
Choose the vent type and fill out the corresponding table.
* See equivalent length tables above.
Example of calculation:
Twin tube (parallel) with terminal
Combustion air length : 24 ft with elbow 3 x 90°
Vent length : 24 ft with elbow 2 x 90°, elbow 2 x 45°
Calculation:
Equivalent Air Length : (24+3x6+2) x 0.5 = 22 ft
Equivalent Vent Length : (24+2x6+2x3+2) x 0.5 = 22 ft +Total = 44 ft.
6.6.7 Combustion air and vent piping lengths.
In the table below you will find the maximum equivalent pipe length of the vent/air
system based on 3" diameter. These lengths are for single pipe (room air) and twin
pipe and concentric venting systems.
Equivalent vent length table 8
Parallel system
Length tube Number of
elbows 90°
x 6*
Number of
elbows 45°
x 3*
Concentric
terminal
A dd 5 ft.*
Total Multiply with
factor
Equivalent
length
Combustion air
ft ft ft ft ft 0.5 ft
Vent
ft ft ft ft ft 0.5 ft
ft Total equivalent len g th
Equivalent friction loss of PVC/CPVC table 9
Fittings or Piping Equivalent PVC
feet m
45 degree elbow 3 0.91
90 degree elbow 6 1.83
plastic pipe per foot 1 0.30
concentric vent kit 3 0.91
Centrotherm 3" PPs Equivalent lengths for piping fittings
feet meters
45 degree elbow 6 1,83
87 degree long elbow 12 3,66
Termination Tee 12 3,66
Twin Pipe to Concentric Adapter 4 1,22
Low profile wall termination 12 3,66
Velocity Cone 12 3,66
Equivalent friction loss of Centrotherm PPC table 9a
Concentric system
Length concentric
tube, boiler to roof
horizontal
Number of
elbows 90°
x 6*
Number of
elbows 45°
x 3*
Concentric
terminal
A dd 2 ft.*
Total Multiply with
factor
Total equivalent
length
ft ft ft ft ft 1.0 ft
Maximum Equivalent Length (Dimension in Feet) - Model & Vent Type Specific
Item # Vent type
E60SR
E85SR
E110SR
feet
1 2” PPS Single Pipe (Room Air) & Twin Pipe 4 0
2 3” PPS Single Pipe (Room Air) & Twin Pipe 100
3 2” PPS Twin Pipe to 2”/4” PPS Cnctrc. Termination 40
4 3” PPS Twin Pipe to 3”/5” PPS Cnctrc. Termination ---
5 3”/5”PP Concentric Pipe 100
6 2 0
7 50
8
2” Flex Vent
3” Flex Vent
100
3” PVC/CPVC Single Pipe & Twin Pipe w/or without 3” CVK Termination