Combustion Air And Vent Piping Lengths - Rinnai E85SRN Installation & Servicing Instructions Manual

6.6.7 Combustion air and vent piping lengths.

Fittings or Piping Equivalent PVC
45 degree elbow
90 degree elbow
plastic pipe per foot
concentric vent kit
Equivalent friction loss of PVC/CPVC
Parallel system
Length tube
Combustion air
ft
Vent
ft
Concentric system
Length concentric
tube, boiler to roof
horizontal
ft
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.
Maximum Equivalent Length (Dimension in Feet) - Model & Vent Type Specific
Item # Vent type
1 2" PPS Single Pipe (Room Air) & Twin Pipe
2 3" PPS Single Pipe (Room Air) & Twin Pipe
3 2" PPS Twin Pipe to 2"/4" PPS Cnctrc. Termination
4 3" PPS Twin Pipe to 3"/5" PPS Cnctrc. Termination
5 3"/5"PP Concentric Pipe
6 2" Flex Vent
7 3" Flex Vent
8
3" PVC/CPVC Single Pipe & Twin Pipe w/or without 3" CVK Termination
Equivalent vent length
feet m
3 0.91
6 1.83
1 0.30
3 0.91
table 9
Calculation of equivalent length vent system
Choose the vent type and fill out the corresponding table.
* See equivalent length tables above.
Number of Number of
elbows 90° elbows 45°
x 6* x 3*
ft
ft
Number of Number of
elbows 90° elbows 45°
x 6* x 3*
ft
Example of calculation:
Twin tube (parallel) with terminal
Combustion air length
Vent length
Calculation:
Equivalent Air Length
Equivalent Vent Length
Centrotherm 3" PPs Equivalent lengths for piping fittings
45 degree elbow
87 degree long elbow
Termination Tee
Twin Pipe to Concentric Adapter
Low profile wall termination
Velocity Cone
Equivalent friction loss of Centrotherm PPC
Concentric Total
terminal
Add 5 ft.*
ft ft
ft ft
Total equivalent length
Concentric Total
terminal
Add 2 ft.*
ft ft
: 24 ft with elbow 3 x 90°
: 24 ft with elbow 2 x 90°, elbow 2 x 45°
: (24+3x6+2) x 0.5
: (24+2x6+2x3+2) x 0.5
feet meters
6
12
12
4
12
12
table 9a
Multiply with Equivalent
factor length
ft 0.5
ft 0.5
Multiply with Total equivalent
factor length
ft 1.0
= 22 ft
= 22 ft +Total = 44 ft.
E60SR
E85SR
E110SR
feet
40
100
40
---
100
20
50
100
table 8
1,83
3,66
3,66
1,22
3,66
3,66
ft
ft
ft
ft
37